Early detection of lung function decrements in children and adolescents with cystic fibrosis using new reference values.

Abstract

Zapletal 86.6% (SD 20.6), GLI79.9% (SD 20.3) and 32% (n=497/1543) were misclassified as normal when using Zapletal. Despite showing no overall differences in FEV1 and forced vital capacity (FVC) between concomitant Pseudomonas detection (PA+) in n=938 and Pseudomonas negative (PA-) (n=2781) using either reference PA+ resulted in lower FEV1 and FVC values with increasing age; however, measurement of small airway obstruction with forced expiratory flow at 75% of FVC (FEF75) values - available for Zapletal -showed significant differences. Reassurance regarding lung function when using old reference values may occur with potential clinical significance. Discrepancies in lung function interpretation underline the importance of using uniform and best available reference values.